1. Field of the Invention
The present invention relates to a fluid dispensing control system useful for automatically filling containers of different sizes with a beverage, and for tallying how many containers of each size have been filled, and what total volume of beverage has been dispensed.
2. Description of the Prior Art
It is very common in restaurants, bars, and other retail food operations to dispense beverages such as soft drinks or milk via set of dispensing heads connected to a common supply source. Each head includes one or more valve-operated spouts through which the beverage flows into a cup or other container that is placed below the spout.
Most commonly, pouring begins when the container is pressed against a rocker-arm situated just below the spout. This arm either mechanically or electrically actuates the spout valve. The valve is held open, and fluid flow continues, for as long as the container is held against the rocker-arm.
Several shortcomings are associated with such a system. The most important is that no accurate tally can be obtained automatically of the number of containers of different sizes that have been filled. The attachment of a counter to the spout actuating rocker-arm is unsuccessful for this purpose. Even if the rocker-arm was pressed just once as each container is filled, the resultant count would correctly report on how many containers were filled, but not how many of each size. Such a total count would not be useful in calculating the monetary value or total price of the dispensed beverage. Moreover, in practice such a system would not even give an accurate tally of the number of filled containers. This is because the rocker-arm often is pressed two or three times as a single container is filled. Thus the operator will press the container against the rocker-arm until the cup is substantially full. He will then withdraw the cup from the rocker-arm to observe the fill level, or in the case of carbonated beverages, to let the carbonation settle down. He will then press the container against the rocker-arm again to complete filling. Obviously a count of the number of times the rocker-arm is actuated will not accurately indicate the total number of containers that have been filled.
There are several reasons why it is desirable to have an accurate count of how many containers of each size have been filled. First, this provides an accurate accounting check, since the number of containers of each size, times the price per size should correspond to the money collected by the cashier. Discrepancies can indicate cashier error, situations in which an employee or customer pours a beverage but forgets to charge or pay for it, or outright theft. Further, by knowing the volume of each container size, a count of the number of filled containers readily can be converted to an accounting of the total volume of beverage that has been dispensed. This permits accurate inventory control, and gives advance notice that the supplies must be replenished or reordered.
To obtain an accurate, automatic count of how many containers of different size have been filled requires some means for size recognition. An object of the present invention is to provide a fluid dispenser in which such size recognition is accomplished automatically. In one embodiment, photoelectric sensors are used in the size determination function. Several problems are associated with the use of photosensors, and it is a further object of this invention to overcome such problems. For example, as the container first is placed beneath the spout, careless initial placement or movement of the cup may actuate the photosensors associated with a container of a different size. To eliminate this problem, the present invention includes circuitry for delaying size recognition and tally until the container can be fixed in place and an accurate determination of size accomplished. A cognate problem occurs if the container is moved during the pouring operation. A further object of the present invention is to provide lockout circuitry which maintains the size determination unchanged during the pouring operation despite such movement of the container.
Another problem associated with the use of photoelectric sensing of container size has to do with changes in ambient light level. Another object of the present invention is to provide circuitry which automatically compensates for such ambient light variation, thereby insuring accurate container sensing regardless of such variation. The same circuitry insures a positive determination despite "chatter" which may result as light is reflected into the photosensors while a container is being moved into place.
Yet another object of the present invention is to provide automatic timing of the pouring operation. Thus once the container size has been established, the correct volume of fluid will be dispensed automatically. Consistent full volume dispensing is achieved, without the need for the user to actuate a rocker-arm multiple times to accomplish complete filling. Uniformity of fill volume also results.